Yoshino Kogyosho Co., Ltd.

Yoshihiro Iimura

Daisuke Uesugi

Koji Yamanaka

Tadao Hirasawatsu

Yukio Kawahara

A method for thermally crystallizing a neck of a primary molded product for forming a bottle-shaped container made of polyethylene terephthalate as principal ingredient, said neck having a functional part and a neck ring at a lower end thereof, said functional part being formed with screw threads at an upper portion thereof and a bead ring below the screw threads, said method comprising: heating the neck, and then squeezing the bead ring heated to the heat-deformable temperature, from outside so as to form an outer diameter of the bead ring within a dimensional tolerance for deformation with regard to sealing effect.

Crystallization method of neck of primary molded product for biaxially-oriented blow-molded bottle-shaped container and jig to be used for the same

A method for producing bottle-type containers made of a synthetic resin, e.g., polyethylene-terephthalate resin, includes a heat treatment step for heating and crystallizing a neck portion of a perform corresponding to a neck portion of a container. In a first stage of the heat treatment step, the neck portion of the perform is temporarily heated to a temperature below a melting point of the synthetic resin, e.g., approximately 200&#xb0; C. to 230&#xb0; C. in the case of polyethylene terephthalate resin. In a subsequent second stage, the neck portion is maintained at a temperature within a range in which crystallization of the synthetic resin is promoted, e.g. approximately 170&#xb0; C. to 195&#xb0; C. in the case of polyethylene terephthalate resin.

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Matsudo, Japan

Yoshihiro Iimura